Editing Shapur II (section)

=== Objectives ===
Ever since the "humiliating" [[Peace of Nisibis (299)|Peace of Nisibis]] concluded between Shapur's grandfather [[Narseh]] and the Roman emperor [[Diocletian]] in 298, the borders between the two empires had changed largely in favor of the Romans, who in the treaty received a handful of provinces in [[Mesopotamia]], changing the border from the [[Euphrates]] to the [[Tigris]], close to the Sasanian capital of [[Ctesiphon]].{{sfn|Kia|2016|p=275}}{{sfn|Shahbazi|2004|pp=464-465}} The Romans also received control over the kingdoms of [[Kingdom of Iberia (antiquity)|Iberia]] and [[Kingdom of Armenia (antiquity)|Armenia]], and gained control over parts of upper [[Media (region)|Media]] in Iran proper.{{sfn|Kia|2016|p=275}} Shapur's primary objective was thus to nullify the treaty, which he spent much of his reign trying to accomplish.{{sfn|Kia|2016|p=275}}

Another cause for Shapur's wars against the Romans was their attempts to meddle in the domestic affairs of the Sasanian Empire and hurt Shapur's kingship by supporting his brother [[Hormizd (son of Hormizd II)|Hormizd]], who had been well received at the Roman court by [[Constantine the Great]] and made a cavalry commander.{{sfn|Shahbazi|2004|pp=461-462}}{{sfn|Kia|2016|p=275}} Shapur had made fruitless attempts to satisfy his brother, even having his wife sent to him, who had originally helped him escape imprisonment.{{sfn|Shahbazi|2004|pp=461-462}} However, Hormizd had already become an avid [[philhellene]] during his stay with the Romans, with whom he felt at home.{{sfn|Shahbazi|2004|pp=461-462}} Another reason was Constantine's declaration of Christianity as the official religion of the Roman Empire in 337. He had also declared himself the defender of all the Christians in the world, including those living in the Sasanian realm.{{sfn|Kia|2016|p=275}}